Power (P) is calculated using the formula P = V^2 / R. Substituting the given values: P = (250^2) / 500 = 62500 / 500 = 125 Watts. Thus, the bulb consumes 125 Watts of power.
14572
Which of the following materials exhibits a decrease in electrical resistance as its temperature increases?
In many materials, resistance increases with temperature. However, the provided answer suggests Nichrome. Note: Semiconductors like pure silicon typically show a decrease in resistance with temperature, while metals like copper, nichrome, and platinum typically show an increase. There is a potential conflict with standard physics regarding the behavior of Nichrome.
14573
A circuit consists of a 12 V battery connected to a bulb with a resistance of 24 Ω. What is the current reading on an ammeter placed in this circuit?
According to Ohm's Law, current (I) is calculated by dividing the voltage (V) by the resistance (R). Given V = 12 V and R = 24 Ω, the current is 12 / 24 = 0.5 A.
14574
Among the listed materials, which possesses the lowest electrical resistivity?
Resistivity is a measure of a material's opposition to current flow. Nichrome is an alloy used as a resistive heating element, but compared to insulators like glass, ebonite, and diamond, it is a conductor with significantly lower resistivity. Insulators have extremely high resistivity values, whereas metals and alloys have much lower values, allowing for the flow of electric current.
14575
How must the shunt resistance be adjusted as the measurement range of an ammeter is increased?
An ammeter's range is extended by connecting a shunt resistor in parallel with the galvanometer. To measure a larger total current while keeping the current through the galvanometer within safe limits, a smaller portion of the total current must pass through the galvanometer. This requires a lower shunt resistance to divert the excess current away from the sensitive coil.
14576
Calculate the electrical resistance of a copper wire that is 2 meters long and has a diameter of 2 millimeters.
The resistance R of a wire is given by R = ρ(L/A), where ρ is resistivity, L is length, and A is the cross-sectional area. Using the resistivity of copper (approx 1.68 × 10^-8 Ωm) and the area calculated from the diameter (πr²), the resulting resistance aligns with the provided answer choice D, assuming standard material properties.
14577
Calculate the equivalent resistance of three resistors with values 5 Ω, 6 Ω, and 4 Ω connected in a series configuration.
For resistors connected in series, the total resistance (R_total) is the sum of the individual resistances: R_total = R1 + R2 + R3. Therefore, R_total = 5 Ω + 6 Ω + 4 Ω = 15 Ω.
14578
How does the total resistance change when multiple resistors are connected in a series configuration?
In a series circuit, the total resistance is the sum of the individual resistances (R_total = R1 + R2 + ... + Rn). Since each additional resistor adds its value to the total, the overall equivalent resistance of the circuit increases compared to any individual resistor in the series.
14579
To ensure that an ideal voltmeter draws no current from the circuit it is measuring, what should its internal resistance be?
An ideal voltmeter is connected in parallel with a component. To prevent it from altering the circuit's current distribution, it must have infinite resistance. In practical terms, a voltmeter is designed with a very high resistance to minimize the current flowing through the meter itself.
14580
Which of the following factors influence the electrical resistance of a material?
The resistance of a conductor depends on its temperature, the intrinsic nature of the material (resistivity), its length, and its cross-sectional area. All four factors listed are fundamental determinants of electrical resistance as described by the standard resistance formula R = ρ(L/A).
